Michael Jackson impersonator Juan Carlos Gomez drinks some water as he takes a break from posing for photos with tourists along The Strip, Friday in near-record high heat. / Julie Jacobson AP

by Doug Stanglin, USA TODAY

by Doug Stanglin, USA TODAY

Temperatures in Las Vegas shot up to 115 degrees on Saturday afternoon, just two degrees shy of an all-time record, as the Desert Southwest continued to stagger under a relentless heat wave.

Las Vegas fire and rescue spokesman Tim Szymanski told the Associated Press that a man died and another was hospitalized in serious condition Saturday afternoon in heat-aggravated incidents as a heat wave blistered this sunbaked city.

The heat wave has sent more than 40 other people to hospitals in Las Vegas since it arrived Friday. On Friday, 115-degree heat in the city tied a 19-year record.

Large swaths of California sweltered under extreme heat warnings, which are expected to last into Tuesday night - and maybe even longer.

In Southern California, Palm Springs peaked at 122 while the mercury in Lancaster set a record at 111, according to the L.A. Times.

The forecast for Death Valley in California called for 128, but it was a few degrees shy of that, according to unofficial reports from the National Weather Service. Death Valley's record high of 134, set a century ago, stands as the highest temperature ever recorded on Earth.

Phoenix hit 119 by mid-afternoon, breaking the record for June 29 that was set in 1994.

The heat is the result of a high-pressure system brought on by a shift in the jet stream, the high-altitude air current that dictates weather patterns. The jet stream has been more erratic in the past few years.

Officials said personnel were added to the Border Patrol's search-and-rescue unit because of the danger to people trying to slip across the Mexican border. At least seven people have been found dead in the past week in Arizona after falling victim to the brutal desert heat.

At Lake Mead National Park, about 30 miles east of Las Vegas, rangers on Saturday staked out major trail heads to discourage hikers from exploring the more rugged areas.

Vanover said the more challenging trails take hikers through ravines and down to the Colorado River. "But when you turn around, it's uphill, rugged rocks," she says.

Three weeks ago, rangers summoned by a 911 cellphone call found a 69-year-old adult Boy Scout leader dead of apparent heat-related illness deep in the park. Another adult and four Scouts in the group were also overcome by the heat and had to be rescued.